package gr.aueb.mscis.utils;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * This class produces Sha1 hashes based on a given String
 * 
 * @author lupin
 * 
 */
public class Sha1 {

	private static byte[] input;

	public Sha1(String strToSHA, boolean hashed) {
		if (hashed)
			input = strToSHA.getBytes();
		else {
			try {
				byte[] theTextToDigestAsBytes = strToSHA.getBytes("8859_1"/* encoding */);

				MessageDigest md = MessageDigest.getInstance("SHA");
				md.update(theTextToDigestAsBytes);
				input = md.digest();

			}// try
			catch (UnsupportedEncodingException uee) {
			}// catch UEE
			catch (NoSuchAlgorithmException nsae) {
			}// catch NSAE
		}
	}

	public static String getHash(String str) {
		MessageDigest digest = null;
		input = null;

		try {
			digest = MessageDigest.getInstance("SHA-1");
			digest.reset();
			input = digest.digest(str.getBytes("UTF-8"));

		} catch (NoSuchAlgorithmException e1) {
			e1.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		return convertToHex(input);
	}

	public static String getHash(byte[] data) {
		MessageDigest digest = null;
		byte[] input = null;

		try {
			digest = MessageDigest.getInstance("SHA-1");
			digest.reset();
			input = digest.digest(data);

		} catch (NoSuchAlgorithmException e1) {
			e1.printStackTrace();
		}
		return convertToHex(input);
	}

	private static String convertToHex(byte[] data) {
		StringBuffer buf = new StringBuffer();
		for (int i = 0; i < data.length; i++) {
			int halfbyte = (data[i] >>> 4) & 0x0F;
			int two_halfs = 0;
			do {
				if ((0 <= halfbyte) && (halfbyte <= 9))
					buf.append((char) ('0' + halfbyte));
				else
					buf.append((char) ('a' + (halfbyte - 10)));
				halfbyte = data[i] & 0x0F;
			} while (two_halfs++ < 1);
		}
		return buf.toString();
	}

	public String toString(byte[] digest) {
		String temp = "";

		for (byte b : digest) {
			String a = Integer.toHexString(b & 0xff);

			if (a.length() == 1) // one digit
				a = "0" + a.toUpperCase()/* +" " */;
			else
				a = a.toUpperCase();

			temp += a;
		}// for each byte

		return temp;
	}// toString

	public byte[] getByteArray() {
		return input;
	}
	
	public String toString()
	{
		String temp = "";
		
		for (byte b : input)
		{
			String a = Integer.toHexString(b&0xff);
			
			if(a.length() == 1) //one digit
				a = "0"+a.toUpperCase()/*+" "*/;
			else
				a = a.toUpperCase();
				
			temp += a;
		}//for each byte
		
		return temp;
	}//toString

}
